/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2005-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.coverage;
import java.util.Arrays;
import java.util.Set;
import org.geotools.factory.Hints;
import org.geotools.factory.FactoryFinder;
import org.geotools.factory.FactoryCreator;
import org.geotools.factory.FactoryRegistry;
import org.geotools.factory.FactoryRegistryException;
import org.geotools.coverage.grid.GridCoverageFactory;
import org.geotools.resources.LazySet;
/**
* Defines static methods used to access the application's default
* {@linkplain GridCoverageFactory factory} implementation.
*
* @since 2.4
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux
*/
public final class CoverageFactoryFinder extends FactoryFinder {
/**
* The service registry for this manager.
* Will be initialized only when first needed.
*/
private static FactoryRegistry registry;
/**
* Do not allows any instantiation of this class.
*/
private CoverageFactoryFinder() {
// singleton
}
/**
* Returns the service registry. The registry will be created the first
* time this method is invoked.
*/
private static FactoryRegistry getServiceRegistry() {
assert Thread.holdsLock(CoverageFactoryFinder.class);
if (registry == null) {
registry = new FactoryCreator(Arrays.asList(new Class<?>[] {
GridCoverageFactory.class}));
}
return registry;
}
/**
* Returns the first implementation of {@link GridCoverageFactory} matching the specified hints.
* If no implementation matches, a new one is created if possible or an exception is thrown
* otherwise.
*
* @param hints An optional map of hints, or {@code null} if none.
* @return The first grid coverage factory that matches the supplied hints.
* @throws FactoryRegistryException if no implementation was found or can be created for the
* {@link GridCoverageFactory} interface.
*
* @see Hints#DEFAULT_COORDINATE_REFERENCE_SYSTEM
* @see Hints#TILE_ENCODING
*/
public static GridCoverageFactory getGridCoverageFactory(Hints hints)
throws FactoryRegistryException
{
if (hints != null && hints.containsKey(Hints.GRID_COVERAGE_FACTORY)) {
GridCoverageFactory coverageFactory = (GridCoverageFactory) hints.get(Hints.GRID_COVERAGE_FACTORY);
if (coverageFactory != null) {
return coverageFactory;
}
}
synchronized (CoverageFactoryFinder.class) {
hints = mergeSystemHints(hints);
return getServiceRegistry().getServiceProvider(GridCoverageFactory.class, null, hints, null);
}
}
/**
* Returns a set of all available implementations for the {@link GridCoverageFactory} interface.
*
* @param hints An optional map of hints, or {@code null} if none.
* @return Set of available grid coverage factory implementations.
*
* @since 2.4
*/
public static synchronized Set<GridCoverageFactory> getGridCoverageFactories(Hints hints) {
hints = mergeSystemHints(hints);
return new LazySet<GridCoverageFactory>(getServiceRegistry().getServiceProviders(
GridCoverageFactory.class, null, hints));
}
/**
* Scans for factory plug-ins on the application class path. This method is
* needed because the application class path can theoretically change, or
* additional plug-ins may become available. Rather than re-scanning the
* classpath on every invocation of the API, the class path is scanned
* automatically only on the first invocation. Clients can call this
* method to prompt a re-scan. Thus this method need only be invoked by
* sophisticated applications which dynamically make new plug-ins
* available at runtime.
*/
public static synchronized void scanForPlugins() {
if (registry != null) {
registry.scanForPlugins();
}
}
}